Shift actuators, such as two-position shift actuators, for selectively shifting, or positioning, a shifting mechanism, such as a shift fork or the like are well known in the prior art. Shift actuators allowing a shift to each of at least two preselected positions by preloading an element, usually a resilient element such as a spring, to bias the shift element, usually a shift fork or the like, towards each of the two preselected positions are also well known in the art. Examples of the latter devices are disclosed respectively in U.S. Pat. Nos. 2,754,692; 2,821,089 and; 3,358,517, the disclosures of which are incorporated herein by reference.
The present invention relates to the control of shift actuators of the type utilizing a rotational member for moving a shift member engagement means between at least two spaced-apart shift positions including the shift actuator disclosed in U.S. Pat. No. 4,428,248 issued Jan. 31, 1984, and assigned to the assignee of the present invention, the disclosure of which is included herein by reference.
Although shifting actuators of the type utilizing a rotational member described above may be used to advantage, a need has existed for providing a simple and low cost method of effective control.